Increasing iPhone Storage: Why Capacity Doesn’t Increase Even After Deleting Photos

When you open the iPhone storage screen, you’ll see a gray bar labeled System Data at the end of the graph. On some devices, it takes up several gigabytes, or even 20–30GB in extreme cases. However, there is no button to delete it when tapped.

It isn’t just one thing. It’s a bundle of app caches, system logs, Safari web data, downloaded software update files, and temporary files from streaming apps. Therefore, you shouldn’t approach it as “how to delete System Data,” but rather “how to reduce each component within it.”

Deleting photos does not reduce this category. This is why your storage capacity might remain the same no matter how many photos you delete.

1. Start by Clearing App Caches

This is the most effective step with no downsides.

Safari — Go to Settings → Safari → Advanced → Website Data to see how much each site is using. It’s common for this to reach several gigabytes. Tapping “Remove All Website Data” will clear it, but you will be logged out. You can also choose to delete data for individual sites. The Offline Reading List is also a target for cleanup here.

Streaming Apps — YouTube, Netflix, and music apps accumulate large offline playback files and temporary files. Check the download sections within each app’s settings to delete them.

Messengers — Apps like KakaoTalk (카카오톡) have a storage management menu within their own settings. Clearing the cache here is highly effective.

Offload Unused Apps — This is a feature available for each app under Settings → General → iPhone Storage. It deletes the app itself but keeps its documents and data. Reinstalling the app restores your previous state. This is useful for large apps you use only occasionally.

2. Reboot and Give It Time

Restarting your device clears some temporary files. While the reduction isn’t massive, it’s free and has no side effects.

System Data is also something iOS manages automatically. When storage gets low, iOS clears caches on its own. This is why you might see a reduction a few days later rather than immediately after a cleanup.

The trick of changing the date and time zone to clear caches, which circulates online, lacks a solid basis. Reviews are mixed between those who saw results and those who saw no change. Manually changing time settings can disrupt certificate verification, alarms, schedules, and logins for some apps. We do not recommend this. Method 3 below is the reliable way.

3. The Surefire Method: PC Backup and Restore

This is the only guaranteed way to truly minimize System Data. The principle is simple: backups only contain user data, not caches and logs. When you restore, System Data is rebuilt from scratch, eliminating the accumulated clutter.

The steps are as follows:

1. Connect your device to a Mac via Finder or a Windows PC via the Apple Devices app (or iTunes) using a cable.
2. Select “Back up all of the data on your iPhone to this Mac/computer” and turn on Encrypt local backup to preserve Health and Keychain data.
3. Once the backup is complete, go to Settings → General → Transfer or Reset iPhone → Erase All Content and Settings on your device.
4. On the initial setup screen, restore from the backup you just created.

This takes a long time. Depending on your device’s capacity, it can take over an hour, and additional time is needed for photos and apps to redownload after restoration. Perform this when you have a day to spare.

Two things to check before starting: You must enable backup encryption to restore saved passwords and Health data. Also, verify the backup date in the list to ensure it actually completed before proceeding with the erase. Skipping these steps can lead to unrecoverable data loss.

4. Preventing It from Accumulating Again

• For photos, enabling iCloud Photos → Optimize iPhone Storage keeps originals in the cloud and only small versions on the device. Since the free 5GB isn’t enough, this is meaningful when using a paid plan.
• Turn off automatic downloads in streaming apps.
• Check Safari website data every few months.
• Set unused apps to be automatically handled via “Offload Unused Apps.”

In summary, Method 1 is a safe cleanup you can do anytime, while Method 3 is a thorough cleanup that requires time. For most people, Method 1 will free up enough space.

⚠️ Menu names and paths may vary depending on the iOS version. This article is based on August 2026, and any task involving a reset must be performed only after confirming a complete backup.

Frequently Asked Questions

Is there no way to delete System Data directly?

No. There is no button in Settings to delete that specific category. You can only reduce the individual components (app caches, Safari data, downloaded files) or reconstruct the whole thing via backup and restore.

Does it really decrease after backup and restore?

Yes, it does. Because backups do not include caches and logs, System Data is newly created upon restoration. However, it will accumulate again over time, so it’s not a permanent fix, and since it’s time-consuming, it’s not something to do frequently.

Does uploading photos to iCloud free up device space?

Only if you have “Optimize iPhone Storage” turned on. If this setting is off, originals remain on the device. Also, since the free iCloud capacity is only 5GB, a paid plan is usually required for a practical effect if you have many photos.

Is the date-changing method effective?

We do not recommend it. Reviews on its effectiveness are mixed and lack a solid basis. Manually changing time settings can cause certificate verification errors, alarm/schedule malfunctions, and login issues with some apps. If you need a thorough cleanup, choose the backup and restore method.